Maxim Integrated MAX15301 PMBus Command Set - Manual (Page 16)

MAX15301 PMBus Command Set User’s Guide
Rev 1 Page 16 of 53
INTERLEAVE
ADDR1 pins, unless a non-zero value of INTERLEAVE has been written to the User Store. The value of
the ADDR0 and ADDR1 pin resistance is measured only once during initialization (power-up).
Because the MAX15301 uses one of two different PWM “speed modes” depending on the switching
frequency selected (see
FREQUENCY_SWITCH ), the INTERLEAVE command will show unexpected
results if switching frequency crosses the 475kHz speed-mode boundary after initialization.
The MAX15301 includes enhancements beyond the PMBus specification INTERLEAVE command
functionality:
• Setting the “Number In Group” to zero will be interpreted by the MAX15301 as 16 possible
phases. This allows phase-spreading in 22.5º increments.
• The low nibble of the high byte of INTERLEAVE contains the “Group ID Number” per the
PMBus specification, but this is a value that has no function and no dependent parameters in
either the MAX15301 device or in the PMBus specification. As a result, it is not necessary to
set a “Group ID Number.” Both nibbles of the high byte of INTERLEAVE can be used
separately or together as “scratchpad” data, if desired.
Output Voltage Sequencing Commands
POWER_GOOD_ON
Reference: Standard Command Lockable: Yes
Command Code: 0x5E Format: Unsigned integer mantissa
Data Bytes: 2 Units: V
Transfer: Read/Write Word Factory Value: 0x1135 (see Description)
Description/Notes: See Section 15.32.1 of the PMBus Specification Part II.
POWER_GOOD_ON mantissa data sent to and from the MAX15301 must be divided by 4096 to
determine the actual voltage value, according to the fixed value of
VOUT_MODE .
In the MAX15301, there are seven possible output voltage ranges based on seven corresponding
internal feedback divider taps. The MAX15301 hardware has 8-bit resolution for the power-good
threshold within each of these seven ranges.
The desired value of POWER_GOOD_ON is retained in memory, regardless of limitations imposed by
the feedback divider range and the 8-bit fault limit resolution, but the read-back value is based on
actual hardware register settings.
The factory value of 0x1135 (1.080V) will be overridden during initialization to
VOUT_COMMAND x 0.95, unless a specific value has been written to the User Store.